User Guide

  • 2020
  • 06/18/2020
  • Public Content
Contents

Suitability Report, Site Details, Task Row

If you choose a
Target System
of
CPU
, to view detailed characteristics of the selected site and its tasks and locks, click the
Site Details
tab. The Task row shows the statistics for that task.
You can reduce Task overhead by combining multiple task executions into a single task execution, for example by:
  • Lexically merging two tasks into one.
  • Enabling
    chunking
    . Chunking means that the parallel framework merges several tasks into a single task, with little or no overhead between them. For instance, if tasks are loop iterations, chunking would execute several iterations together (as a chunk) before heavyweight task control is performed. Chunking is typically implemented when you convert to a parallel framework by using an
    Intel® Threading Building Blocks (Intel® TBB)
    parallel_for()
    instance, an OpenMP* C/C++ pragma
    #pragma omp parallel for
    , or the OpenMP* Fortran directive
    !$omp parallel do
    .
If you see an Annotation Label named
_too_deep_
, this indicates that the call behavior of your program results in nesting of site and/or task annotations more deeply than
Intel Advisor
can handle. The deeper occurrences have all been merged into this
_too_deep_
pseudo-site. This can indicate a problem with the placement of the annotation pair. For example, deep recursions or not executing site-end or task-end annotations can result in such nesting.

For Each Site, Decide Whether to Modify or Keep Annotations

Use the
Suitability Report
window to view the predicted parallel performance of each parallel site and its impact on the
Maximum Program Gain for All Sites
. For example, if a site either has a
Site Gain
of less than 1.0 or does not contribute to
Maximum Program Gain for All Sites
, modify or remove its annotations. In contrast, any site that contributes to
Maximum Program Gain for All Sites
should be kept. For most sites, carefully examine the annotations, overhead assumptions, and related code.
In the upper-right part of the
Suitability Report
pane, if multiple parallel sites were detected during target execution, select a different Site row to display its details.

Implementing Modeling Assumptions Later When Adding Parallel Code

In the lower-right part of the Suitability Report under
Runtime Modeling
, changing a checkmark does not resolve an issue - it configures the modeling of your proposed parallel program execution. To implement the modeled improvements indicated by the check boxes, use specific parallel framework constructs in the
Add Parallel Framework
step of the workflow and consider .

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804